Treatment of hydrocarbons



l Sept. 2, 1930. E. B. PHILLIPS ET AL TREATMENT OF HYDROCARBONS Filed July 22, 1927 N\ A H I.

INVENTOR t5. Phz'llz' I'rnes Mi; G

Patented Sept. 2, 1930 UNITED STATES PATENT OFFICE ERNEST B. PHILLIPS, OF EAST CHICAGO,

AND JAMES G. STAFFORD, OF WHITING,

INDIANA, ASSIGNORS TO SINCLAIR REFINING COMPANY, OF NEW YORK, N.Y., A

CORPORATION OF MAINE Application filed July 22,

This invention relates particularly to improvements in the production of light petroleum distillates, such as kerosene, benzine, gasoline and light cracked distillates. The invention includes improvements in the treatment of such light oils and also includes improvements in the treatment of crude petroleum oils from which such light oils are subsequently to be separated.

One of the general .methods employed for some t-ime past in refining light petroleumv oils consists in subjecting them to treatment- With sulphuric acid, then to an alkali treatment and finally to a so-called doctor treatment. Following treatment with sulphuric acid` the oils arebfrequently rerun, that is redistilled, and the alkali treatment may be combined with this redistillation, for exampleby carrying the distillation out over an alkali or an alkaline substance. The doctor treatment is usually -made the final step in the sequence of operations to insure a sweet product.

One of the purposes o .the doctor treatment as it has been employed is the eliminat-ion of objectionable sulphur compounds, including organic sulphides such as the vmercaptans, and, in the caseof oils that have been subjected to previous treatment with sulphuric acid` frequently sulphur-containing compounds introduced as a result of the acid treatment or through decomposition of constituents introduced. by acid treatment, such as the alkyl sulphates. Such sulphur-compounds are objectionable because they tend to render the oil unstable onv exposure to light` and to impart to it bad color and odor and corrosive properties.

l'n the doctor treatment.. as usually carried out. the oil is agita-ted or otherwise brought into intimate contact with the doctor solution and a :so-called break is then efieeted by the addition of elementary sulphur. Due to difficulties of control. there usually remains in the oil either soluble sulphur compounds produced by reaction with the doctor solution or, more frequently, elementary sulphur because of the necessity of employing an excess of sulphur to bring about the break. When the break occurs, the reaction products 1927. Serial No. 207,793.

of the doctor treatment form locky masses which carry down a large part of the objectionable constituents.

This invention provides an improved method of treating light petroleum oils which minimizes difficulties such as those encount-v ered in application of the so-called doctor treatment While at the same time efi'ectin g the purposes of such treatment, in many cases with an actual improvement in the result-s secured'. The invention has several import-,

on petroleum oils which indicate the forma- A tion of sodium cuprate in the alkaline aqueous solution. This treatment may be carried out at ordinary temperatures simplyby agi tating the petroleum oil with the above noted treating solution, in the manner in which such oils are customarily subjected to treatment with aqueous solutions of refining agents. 4The treatment is carried out with particular advantage, however, in connection with the distillation or redistillation of the petroleum oil, particularly Where the oil has previously been subjected to refining treatment with sulphuric acid. Where the treatment is carried out in conjunction with a distilling operation, the oil is heated in a still and vapors are driven o into a reflux tower, the vapors escapingfrom the reflux tower being condensed to form the-distillate product, and an alkaline aqueous solution of the heating agent is introduced into the reiiux tower in direct contact with the vapors of the oil undergoing distillation. The treating solution is advantageously supplied to the refiux tower in the form of an emulsion with additional fresh oil. I

A treating solution suitable for use in carrying out the present invention may be made, for example, by saturating a\ B. aqueous caustic soda solution with black copper oxide at a temperature approaching the boiling point of the solution, say at a temperature approaching 285 F., and subsequently diluting the solution to about 30o B. before use. At elevated temperatures, a B. caustic soda solution will absorb as much as 0.35 to 0.50% of black copper oxide. Before use, and advantageously after dilution, the solution is allowed to stand to permit any undissolved material to settle.

In one way of carrying out the invent-ion, in the treatment of raw kerosene or raw gasoline for example, the oil 1s first Washed with say 1% or somewhat more of 15-30o B. caustic soda solution to eliminate hydrow gen sulphide and other easily removed sulphur and then, after separat-ion of the caustic soda solution, is agitated, with air or mechanically, with from 3 to 5% of a treating solution comprising sodium hydroxide and copper oxide, prepared as previously described, until the oil is doctor sweet. The use of such treating solutions tree lrom undissolved copper oxide is particularly advantageous in such operations. A't'ter agitation, the oil is separated from the treating solution and from any suspended impurities by settling. A. quick clean break is uniformly secured, and this quick clean break is one of the important advantages of the invention. The separated oil is then washed with water and may be subjected to a variety of subsequent treatments.

For example, the separated oil may he subjected to a light treatment with sulphuric acid, with say from 1 to 4 pounds of acid per barrel, and after separation of acid sludge agitated with from 1/2 to 3 pounds per barrel of fine fullers earth until all traces of acidity are removed. The tullers earth may then be separated from the oil in any convenient manner, for example by settling or by filtration.

As another example, the separated oil from the treatment with the alkaline aqueous solution containing sodium hydroxide and copper oxide. after washing, may be contacted with dry cupric chloride. as described in an application tiled May Q0. 1926, Serial No. 112.638. Following the cupric chloride treatment, the oil may be subjected to a light treatment with sulphuric acid or it may be treated directly with t'ullers earth, as also described in the application just ret'erred to. V[t the oil is treated with sulphuric acid following the cupric chloride treatment. it is :ulvantageous to etlect neutralimtion o'l` any remaining acid by treatment with tine tullers construction, and a alkaline aqueous solution comprising sodium hydroxide and copper oxide is introduced into the reflux tower in direct contact with the vapors therein, for example as an emulsion with additional oil supplied to the distillation. The treating solution may be prepared as previously described or it may contain a somewhat greater proportion of copper oxide. The treatingr solution so supplied to the distilling operation, for example, may.l amount to from l to 4% of the oil supplied to the operation. The distillation may be carried out on a batch basis, or on a continuous basis, that is with supply of fresh oil and discharge of residue during the operation.

One form of apparatus. adapted for use in carrying out the invention in this way, is

diagrammatically illustrated in the accompanying drawing.

The still l is of conventional construction. A charging line Q is provided for initially charging the still and a draw off line 3 for the. discharge. ot residual oil. Arranged above the still is a reflux or tractionating tower 4 provided with a continuous helical baille to permit contact with heat exchange between liquid and vapor components within the tower without spraying liquids through the vapors or bubbling vapors through liquids. This type of tower is particularly useful in carrying out the invention but other types ot towers may also be used. The vapors escape from the top of the tower through vapor line 5 to the condenser 6 where they are condensed to form the distillate product run olf through the look box connection 7 To assist in control of the tower, a light fraction, such for example as a part of the distillate produce or a fraction of corresponding character, may be introduced through connection 8. Fresh oil is introduced near the upper end of the tower through connection 9 by means of centrifugal pump l0. onnection ll, including control valve 13, opens into the intake connect-ion 12 of the pump l0.

ln distillation of the oil being treated in the apparatus illustrated` the oil. or the lighter part of the oil. is vaporized in the still l, the heavier components ot the vapors are condensed in the tower 4 and refluxed to the still, and the vapors escaping from the tower At are condensed to I'orm the distillate product in the. condenser 6.

'lhe treatin, r solutipn is supplied through connection ll and, in the pump, is emulsilied with fresh oil flowing to the. pump through connection l2 so that the treating solution enters the upper part ol the tower 4 through connection 9 intimately mixed willi fresh oil. In the tower, the treating solution is brought into intimate and effective contact with the vapors ot the oil undergoing distillation and with the liquid condensate retluxed to the still. All of the oil is thus cllectively slib- Y sulphurio acid in the usual way.

jected to treatment with the treating solution, including the products of any decomposition taking place in the tower 4. The various reaction products, and -any residue of the treating solution,l are carried downwardly into the still with the unvaporized or condensed oil and are removed from the still,'in continuous operation, largely in suspension in residual oil discharged from the still.

In carrying out the invention in this way, finished gasolines, for example, can be obtained directly as the distillate product without further treatment from naphtha fractions, from crude oils or cracked oils or mixtures of the two, which have been subjected to previous reningtreatment with rllhe invention is also useful in the direct treatment oi? crude petroleum oils from whichv light petroleum oils are to be separated. ln carrying out the invention, in the treatment of crude petroleum oils, thevapors driven oil from the crude oil during distillation, to

separate light oils such as kerosene, benzine and gasoline, are subjected to treatment with an alkaline aqueous solution comprising sodium hydroxide and copper oxide prepared as previously described.

The crude oil may be subjected to distillation in a still provided with a reflux tower, of the general type illustrated in the drawing and just described, and the treating solution introduced into'the reflux tower as described in connection with the rerunning of naphtha character .fractions The treating solution may be so supplied directly to the reiux tower on the crude still as such, or as an emuloxide supplied to the reluxing operation as an emulsion with additional oil.

5. In the distillation of crude petroleum oils, the improvement which comprises subjecting the vapors of the crude oil undergoing distillation to treatment with an alkaline aqueous solution comprising sodium hydroxide and copper oxide free from undissolved copper oxide. l

6. In rerunning petroleum improvement which comprises distilling the naphtha and subjecting the resulting vapors to a reluxing operation in direct contact with an alkaline aqueous solution comprising sodium hydroxide and copper oxide free from undissolved copper oxide.

7. ln rerunning petroleum naphthas, the improvement which comprises distilling the naphtha and subjecting the resulting vapors to a refluxing operation in direct contact withjan alkaline aqueous solution comprising sodium hydroxide and copper oxide supplied to the rei'luxing operation as an emulsion with additional naphtha.

ERNEST B.- PHILLIPS. JAMES G. STAFFORD.

sion in the crude oil, or part of the crude oil,

supplied to the operation, or as an emulsion in a lighter oil, for example, in oil of the 4character of the distillate product. In carrying out the invention in this way., light petroleum oils which are doctor sweet just as they come from the still kand which remain -doctor sweet can be obtained from many crudes.

Ve claim: l j

1. ln reining petroleum oils, the improvement which comprises subjecting the oil to treatment with an alkaline aqueous solution f' Acomprising sodium hydroxidek and copper oxide free from undissolved copper oxide.

2. In reiining petroleum oils, the improvement-which comprises subjecting vapors of the oil to treatment with an alkaline aqueous solution comprising sodium hydroxide and copper oxide free from undissolved copper oxide v 3. In refining petroleum oils, the improvement which comprises distilling the oil and subjecting the yapors of the oil undergoing distillation to a refiuxing operation in direct contact with an alkaline aqueous solution comprising sodium hydroxide and copper oxlde free from undissolved copper oxide.

4.1m rening petroleum oils, the improve- I 

